Controlling apparatus for highway crossing signals



Feb. 9, 1937. P. H. CRAGO- 2,069,874

CONTROLLING APPARATUS FOR HIGHWAY CROSSING SIGNALS Filed April 5, 1935 INVENTOR Paul H. Cpqyo HIS ATTORNEY 55 tery 4.

Patented Feb. 9, 1937 UNHTED STATES AT N'i' Paul H. Grago, Wilkinsburg, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa, a corporation of Pennsylvania Application April 5, 1935, Serial No. 14,891

8 Claims.

My invention relates to controlling apparatus for highway crossing signals, that is, to means for the control of signals which are placed at intersections of railways and highways for the purpose of warning users of the highway when a train is approaching.

One feature of my invention is the provision of means for correctly controlling a highway crossing signal for a track on which trains move in both directions, if conditions are such that the two track sections which control the signal cannot extend through the highway crossing but are separated from each other at the crossing' by a section of track which is longer than a single car or a light engine.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view illustrating one form of apparatus embodying my invention.

Referring to the drawing, the rails I and IA of a stretch of railway track X are divided by insulated joints 2 into sections AB and CD, one extending in each direction from an intersecting highway H. A track relay R, having a distinguishing suflix, according to its location, is connected across the rails I and IA at one end of each of the sections AB and C--D, and a track battery 3 is connected across the rails at the other end of each of these sections. The highway H is protected by a signal S, of any suitable type such, for example, as a bell or light signal or a combination of both, which signal is controlled in part by an interlocking relay K having a. pair of windings 26 and 21, and in part by the track relays RI and R2.

A timing device, here shown as a thermal relay T, is provided for at times controlling the windings 2S and 21 of the interlocking relay K. The relay T has a contact I2 which is open when the relay T is in its initial or deenergized condition and which becomes closed when relay T attains its operated condition a predetermined 45 time interval after energy is applied to the heating element I6.

Under normal conditions, the track relays RI and R2 and both windings of the interlocking relay K are all energized and the thermal relay T 50 is deenergized. The winding 26 of the relay K is energized by virtue of a stick circuit passing from a battery 4, through front or flagman contact 6 of relay K, front point of contact of track relay RI, and winding 26 of relay K back to bat- The winding ll of relay K is energized by a stick circuit passing from battery 4, through front or flagman contact 8 of relay K, front point of contact I of track relay R2 and winding 21 of relay K back to battery 4.

I shall now assume that an eastbound car or engine, that is, a car or engine moving toward the right as shown in the drawing, travelling at normal speed, enters section AB and causes the deenergization of track relay RI. This opens front contact 5 of relay RI and interrupts the .10 stick circuit just traced through this contact for winding 26 of interlocking relay K. The deenergization of winding 26 establishes a signal circuit passing from battery 4, through back contact 9 of track relay RI, back contact ID of relay K and operating mechanism of signal S back to battery 4, thereby causing the signal S to give warning to traffic on the highway H of the approaching car or engine.

When the car departs from section AB, the track relay RI again becomes energized and opens its back contact 9, thereby interrupting the signal circuit previously traced through this contact and discontinuing the operation of the signal S. The energization of track relay RI establishes '25 a circuit passing from battery 4, through the back point of contact 6 of relay K, front contact I5 of track relay R2, front contact II of track relay RI and heating element I6 of thermal relay T back to battery 4. Relay T, however, does not 30 close its contact I2 because this relay is so ad-' justed that it will not attain its operated condition before the car reaches section C D when the car is travelling at its normal speed. As will be explained hereinafter, when the car reaches section C-D energy will be disconnected from relay T.

The car next enters section 0-D and causes the deenergization of track relay R2, thereby causing this relay to open the front point of its 40 contact I and interrupt the circuit for winding 21 of relay K previously traced through this contact. Because the relay K, however, is of the interlocking type, the contacts operated by the winding 2'! are prevented from closing at their back points, and flagman contact 8 is prevented from opening at its front point. When the front point of contact I of relay R2 became opened, the back point became closed to establish a pickup circuit for winding 25 of relay K passing from battery 4, through front point of flagman contact 8 of relay K, back point of contact I of relay R2, front point of contact 5 of relay RI, and winding 26 back to battery 4. This causes the energization of winding 26 of relay K and re- .55

establishes the stick circuit for this winding previously traced through the front point-of its contact 6. The releasing ofrelay RZalso opens When the car departs; from 1, thereby causing the reenergization of winding I this relay which wasimaintained closed "while 'winding'li'l was deenergized by the interlocking character of this relay. The apparatus i's restored to its normal condition.

The thermal relay T functions to restore the interlocking relay K' to its normal condition in the event a, train enters either of the control sections andthe n reverses its direction without proceeding over the opposing control section. If

r for example; an eastbound train enters section A-- B and then reverses its directon so as to clear secton' A--B'without entering section C D, relay RI will be released andthen picked up." The 'deenergization of relay RI will open front point 7 of its contact which will deenergize winding 26 of relay K-and thus cause the signal S to operate. When the train leaves secton AB, the energiz'ationof'relay RI will open the circuit for the signal S and also will close the circuit previouslydescribed for relay T which will apply energy to V heating element I6." When relay T attains its i operated conditionfso that its'contact l2 becomes closed, a pick-up circuit will be established for windingZB which passes from battery 4, through front point of contact 8 of relay K, contact l2 of relay T, front point of contact 5 of-relay'Rl, and.

' Winding 26 back to battery l. --Thus, relay K-will be restored to' its normal position. 7

' A train of sufficient length to occupy aportion' of sections A+B and C-'D simultaneously will not'permit relays RI and R2 both to become energized atthe' same time while such train is traversing sections A-B and C -D. The relay T, therefore, does not operatefor trains of a'length great-. er than: the length of section B-,,C when such- .;trains. are traversing sections .A--B and B-C, be-

' i cause relay'T may be energized only if both track relays RI and R2 are in their energizedconditions.

' apparatus embodying my invention for a west- V o V a divided intoa first section'and a second section While I have not described the operation of thebound train, it is readily apparent that such a train will cause the 'variousparts to'operate in a manner similar to that just described for the e not provided with a track circuit and whichis longer than the length of a single car or light engine. Furthermore I have provided a single time element device which'is'effective for restoring the apparatus to its normal condition'in the "event a train enters either control section and then reverses its direction without proceeding '-over the opposing control section. V

V V V described only one form of apparatus embodying. my in-1 Although I have'herein shown and J vention; it is understoodthatvarious changes and modifications may be'made therein within the scope offlthe, appendedclaims without departing from the spirit and scope of myinvention.

2170i relay K byvirtue of the stick circuit previously traced throughfrorit point of contact 8 of 2,069,874 V i V Having thus described my invention, what I claim is:

'1. In combination, a stretch of. railway track divided into a firstsection and a second section,

a signal, a first relay operable by a car entering said first section for operating said signal, a seceond'relay operable by a car entering sald second 2 section for operating said" signal, a tlmingdevice eifective at times to control either said'first V relay or said second relay,.and means for 0011- trolling said timing device effective when either said first section or said second section'becomes unoccupied aftersuch section has beenoccupied provided the other section is then unoccupied.

2. In combinationga stretch of railway track. divided into a firstxsection and a second section, g

a signal, a first track relay operable by'a car entering saidfirst section for operating said signal; a secondtrack relay operable by a carentering said second section for operating'said signal,

an interlocking relay operable by said first and second track relays for operating said signal jointly with saidfirst and second track relays,' a timing device normally in one condition and. effective when in a difierent condition to control said interlocking relay, and means for at times initiating theoperation of said timing deviceprovided said first andsecond sections are both un- Y occupied.

tersection, a first track'relay associated withsaid 1 3. In .combinatiomastretch' of railway track at 'dividedginto a first section and a second'secti'on; f

separated .from said first section by a stretch,

firstgsection for. controlling saidsignal for railway traiiic moving in one direction, a second track relay associated with said secondsection for controlling said signal for rallway traflic'mo vlngin V an opposite direction, an interlocking relaycon trolled by said first and second track relays for tive when a car movingrfrom one of said sectio'ns 4. In combination, mat h of rai way track controlling said signaljointly with said track rei 1 lays, a timing device normally in onezcondition' and effective, when in a different condition to control said'interlocking relay,1and means for in-I 'itiating the operationof said timing device eflec separated bya stretch of track intersected by a highway, a signal for controlling traffic on said relay associated with said second'section, an in terlocking relay controlled jointly by said first and second trackirelays, a first circuitjor said signal controlled by said first track relay and bysaid interlocking relay, a second circuit for said signal controlled by saidsecond track relay and by said interlocking relayfa thermal relay effective at times to control said interlocking relay, and means for at times controlling'said the'r mal. relay effective only if said first and "second track relays are both energized. I

5. In combination, a stretch'of. railway track Qdivided into a first section and a second section separated from said; first section by a stretch of track-intersected: by a highway a signal for j controlling traflic over' saidhighway at such in- V tersection, a first track relay associated with) said first section for controllingsaid signal for railway trafllc moving over saidstretch in one direction, a second track relay associated with said second section for controlling said signal for railway trafiic moving over said stretch in an opposite direction, a thermal relay, means for controlling said thermal relay effective only if said first and second track relays are both energized, and an interlocking relay controlled by said first and second track relays and by said thermal relay for controlling said signal jointly with said track relays.

6. In combination, a stretch of railway track intersected by a highway, said track being divided to form two sections, a track relay for each section, an interlocking relay having two magnets controlled at times by said two track relays respectively, a thermal relay controlled jointly by both of said track relays and said interlocking relay, a first pick-up circuit for each magnet each such circuit controlled by both of said track relays and by the other magnet, a second pick-up circuit for each magnet each such circuit controlled in part by said thermal relay, a stick circuit for each magnet each such circuit controlled by the respective track relay, and a highway crossing signal located at said intersection and controlled by said interlocking relay.

'7. In combination, a stretch of railway track intersected by a highway, said track being divided to form two sections, a track relay for each section, an interlocking relay having two magnets controlled at times by said two track relays respectively, a thermal relay at times efiective to control one or the other of said magnets, a first circuit for said thermal relay including a front contact of each of said two track relays and a back contact of one magnet, a second circuit for said thermal relay including a front contact of each of said two track relays and a back contact of the other magnet, and a highway crossing signal located at said intersection and controlled by said interlocking relay.

8. In combination, a stretch of railway track intersected by a highway, said track being divided to form two spaced sections extending in opposite directions from the highway, a track relay for each section, an interlocking relay controlled at times by said two track relays respectively, a thermal relay normally in an initial condition and effective when in its operated condition to control one or the other of said magnets, means for initiating the operation of said thermal relay when a car leaves one section and enters the space between the sections, means for causing said thermal relay to assume its initial condition when the car enters the other section, 'and a highway crossing signal located at said intersection and controlled by said interlocking relay.

PAUL H. CRAGO. 

